Muhammad Atta, Sáenz Ezquerro Carlos, Srivastava Rajat, Asinari Pietro, Laspalas Manuel, Chiminelli Agustín, Fasano Matteo
Department of Energy, Politecnico di Torino, 10129 Torino, Italy.
Department of Mechanical Engineering, MUET SZAB Campus, Khairpur Mir's 66020, Pakistan.
Nanomaterials (Basel). 2023 Jun 28;13(13):1960. doi: 10.3390/nano13131960.
This research addresses the need for a multiscale model for the determination of the thermophysical properties of nanofiller-enhanced thermoset polymer composites. Specifically, we analyzed the thermophysical properties of an epoxy resin containing bisphenol-A diglyceryl ether (DGEBA) as an epoxy monomer and dicyandiamide (DICY) and diethylene triamine (DETA) as cross-linking agents. The cross-linking process occurs at the atomistic scale through the formation of bonds among the reactive particles within the epoxy and hardener molecules. To derive the interatomic coarse-grained potential for the mesoscopic model and match the density of the material studied through atomic simulations, we employed the iterative Boltzmann inversion method. The newly developed coarse-grained molecular dynamics model effectively reproduces various thermophysical properties of the DGEBA-DICY-DETA resin system. Furthermore, we simulated nanocomposites made of the considered epoxy additivated with graphene nanofillers at the mesoscopic level and verified them against continuum approaches. Our results demonstrate that a moderate amount of nanofillers (up to 2 wt.%) increases the elastic modulus and thermal conductivity of the epoxy resin while decreasing the Poisson's ratio. For the first time, we present a coarse-grained model of DGEBA-DICY-DETA/graphene materials, which can facilitate the design and development of composites with tunable thermophysical properties for a potentially wide range of applications, e.g., automotive, aerospace, biomedical, or energy ones.
本研究满足了对多尺度模型的需求，该模型用于确定纳米填料增强热固性聚合物复合材料的热物理性质。具体而言，我们分析了一种环氧树脂的热物理性质，该环氧树脂包含双酚A二缩水甘油醚（DGEBA）作为环氧单体，以及双氰胺（DICY）和二亚乙基三胺（DETA）作为交联剂。交联过程在原子尺度上通过环氧和固化剂分子内反应性粒子之间形成键来发生。为了推导介观模型的原子间粗粒度势并通过原子模拟匹配所研究材料的密度，我们采用了迭代玻尔兹曼反演方法。新开发的粗粒度分子动力学模型有效地再现了DGEBA - DICY - DETA树脂体系的各种热物理性质。此外，我们在介观层面模拟了由所考虑的环氧树脂与石墨烯纳米填料混合制成的纳米复合材料，并根据连续介质方法对其进行了验证。我们的结果表明，适量的纳米填料（高达2 wt.%）会增加环氧树脂的弹性模量和热导率，同时降低泊松比。我们首次提出了DGEBA - DICY - DETA/石墨烯材料的粗粒度模型，这有助于设计和开发具有可调热物理性质的复合材料，以用于潜在的广泛应用，例如汽车、航空航天、生物医学或能源领域的应用。
